It's not my article, so I can't answer for the author. I suspect that's
to "freeze the code" for release while others continue to develop
unimpeded. With git that's an easy thing to do.

A decade ago I would tag the head in SVN for a release candidate. If a
problem showed up with that build (very rare) then I would fix it and
repeat with the current head. I didn't use branches.

>
> Why not master ?
> Because it's easier to undo or because of different policies ( candidate
> can fail ) ?
>
> A very simple workflow is indeed "short lived" : pick something small,
> branch from master, commit as often, merge to master with some squash if
> required, push
>
> What does matter finally is how we are comfortable with our history ?,
> Thierry